In order to cool elements for an electronic unit such as computer chips, air-cooling fins made of aluminum and the like have frequently used. However, since the heat-generating amount has been increasing year after year with improvement in performance of those elements, the air-cooling fins have become difficult to cope with them.
Thus, there has been developed a cooling device which transmits heat of those elements to refrigerant to cool those elements by means of movement of-latent heat based on the boiling and condensation of the refrigerant.
An example of a cooling device using the refrigerant has been disclosed in, for example, Japanese Patent Application Laid-Open No. 10-308486. The cooling device disclosed in this official gazette includes, as shown in FIG. 7, a refrigerant container 100 constructed by stacking a plurality of sheets of plates, and radiating fins 110 mounted to the refrigerant container 100 so as to contact a radiating surface thereof.
The above-described cooling device is capable of coping with various cooling capacity by increasing or decreasing a number of sheets of the plates constituting the refrigerant container 100 to thereby change the height of the refrigerant container 100. However, since the surface area of the plates is constant, it is difficult to change the shape of the radiating fins 110 extensively even if the capacity of the refrigerant container 100 is changed. More specifically, in the radiating fins 110 shown in FIG. 7, an extrusion production of aluminum is generally used. Accordingly, in order to change the shape of the radiating fins 110, the need for designing a new extrusion die arises, resulting in very high cost.
Although it is comparatively easy to change the height of the refrigerant container 100, when the heat receiving area and the radiating area are greatly changed according to the number of heat-generating elements 120 or the heat-generating amount thereof, the need for changing the basic size of the plates arises. Therefore, expense required for a press die for manufacturing the plates will become expensive.
As another example of the previously known cooling devices, there is also known a cooling device 500, as shown in FIG. 26, that includes a refrigerant container 510, and a radiating core portion 520 having tubes 540 connected to the refrigerant container 510 and a header tank 560 connected to the other side ends of the tubes 540. The refrigerant container 510 and the header tank 560 are constructed of plural sheets of stacked plates, and are connected by inserting a member into apertures formed in the plates.
In the cooling device 500, a balance between refrigerant-side cooling capability to be adjusted by pressure loss of refrigerant passing through each tube 540, and air-side cooling capability to be adjusted by flow resistance of air passing through a radiating core portion 520 is set, so that the radiating capability of the cooling device 500 is adjusted. As one of means for adjusting the pressure loss of the refrigerant and the air-flowing resistance, an interval of the tubes 540 can be changed. However, in order to change the interval of the tube 540, it is necessary to change also the number of apertures in the plates, into which tubes 540 are to be inserted. For this reason, expense required for a press die for manufacturing the plates becomes expensive with the number change of apertures in the plates.
Further, in the cooling device 500, if the refrigerating container 510 and the header tank 560 are made to be close to each other or if the interval of the tubes 540 is narrow, it is difficult to insert the assembling jig. Particularly, in order to assemble the tube 540 positioned at the central part of the radiating core portion 520, a complicated operation will be needed.